长江口横沙通道近岸冲刷地貌形成机制

doi:10.11821/dlxb201907007

Abstract

Abstract:

The intense erosion of a near-shore riverbed is one of the main factors for the slope failure of a bank. During a detailed investigation carried out in August 2017 and May 2018 of underwater topography of the Yangtze Estuary, a large scour pit was recognized near the shore of the Hengsha passage. The morphological and geometrical parameters of the scour pit were measured using the SeaBat7125 multi-beam system. Dual-frequency ADCP was used to collect hydrodynamic data near the scour pit. Further, a historic nautical chart was digitalized to analyze the evolution and formation mechanism of the scour pit. The results indicated that the scour pit is in the shape of an oval, with a length and width of around 430 m and 150 m, respectively; the deepest point is approximately 38 m below the surrounding riverbed. Since the formation of the -20 m isobaths line in 1992, the scour pit area has been expanding continuously, and the average depth has been increasing yearly; in particular, after 2005, the depth increased sharply. From 1984 to 2017, the riverbed around the scour pit underwent the process of erosion-silting-erosion. In the 33 years, the scouring amount is 3.45×10 ⁷ m ³, and the average scouring depth is 4.68 m. The ebb tide from the North Channel flows into the Hengsha passage, forming a circulation flow, thereby eroding the channel near the west bank of the Hengsha island and forming a scour pit. After 2005, the scour pit grew rapidly and expanded southward. This is mainly because the reclamation engineering performed in North Changxing reduced the curvature radius of the bend that resulted in intensified erosion. The reservoir construction engineering performed in Qingcaosha moved the thalweg in the upper and middle sections of the North Channel, and the northward entrance of the Hengsha passage expanded owing to the ebb current, which is also one of the main reasons for rapid erosion. In addition, the construction of reclamation and deep-water channel projects in the vicinity has contributed to the erosion of the channel bed, thereby accelerating the expansion of the scour pit. It can be seen that human engineering activities are the main driving factors for the rapid development of large scour pits in the Changjiang Estuary.

Key words: the Yangtze Estuary, Hengsha passage, erosional topography, human activity, multi-beam sounding system

HUA Kai,CHENG Heqin,ZHENG Shuwei. Formation mechanism of near-shore erosional topography in the Hengsha passage of the Yangtze Estuary[J].Acta Geographica Sinica, 2019, 74(7): 1363-1373.

Figures/Tables 10

Fig. 1

Fig. 2

Fig. 3

Tab. 1

Fig. 4

Tab. 2

Fig. 5

Fig. 6

Fig. 7

Fig. 8

References 23

[1]	Meade R H, Moody J A . Causes for the decline of suspended-sediment discharge in the Mississippi River system, 1940-2007. Hydrological Processes, 2010,24(1):35-49.
[2]	Monge Ganuzas M, Cearreta A, Evans G . Morphodynamic consequences of dredging and dumping activities along the lower Oka estuary (Urdaibai Biosphere Reserve, southeastern Bay of Biscay, Spain). Ocean & Coastal Management, 2013,77(4):40-49.
[3]	Huo Miao, Fan Daidu, Lu Qi , et al. Decadal variations in the erosion/deposition pattern of Nanhui muddy bank and their mechanism in the Changjiang Delta. Acta Oceanologica Sinica, 2010,32(5):41-51.
	[ 火苗, 范代读, 陆琦 , 等. 长江口南汇边滩冲淤变化规律与机制. 海洋学报, 2010,32(5):41-51.]
[4]	Ji Na, Cheng Heqin, Yang Zhongyong , et al. Sedimentary and morphological evolution of nearshore coast of Yangtze Estuary in the last 30 years. Acta Geographica Sinica, 2013,68(7):945-954.
	[ 计娜, 程和琴, 杨忠勇 , 等. 近30年来长江口岸滩沉积物与地貌演变特征. 地理学报, 2013,68(7):945-954.]
[5]	Li Bing, Yan Xuexin, He Zhongfa , et al. Impacts of the Three Gorges Dam on the bathymetric evolution of the Yangtze River Estuary. Chinese Science Bulletin, 2015,60(18):1735-1744.
	[ 黎兵, 严学新, 何中发 , 等. 长江口水下地形演变对三峡水库蓄水的响应. 科学通报, 2015,60(18):1735-1744.]
[6]	Lu Xuejun, Cheng Heqin, Zhou Quanping , et al. Features and mechanism of asymmetric double-kidneys scoured geomorphology of pier in tidal estuary. Acta Oceanologica Sinica, 2016,38(9):118-125.
	[ 陆雪骏, 程和琴, 周权平 , 等. 强潮流作用下桥墩不对称“双肾型”冲刷地貌特征与机理. 海洋学报, 2016,38(9):118-125.]
[7]	Gao Shu . Changjiang Delta sedimentation in response to catchment discharge changes: Progress and problem. Advances in Earth Science, 2010,25(3):233-241.
	[ 高抒 . 长江三角洲对流域输沙变化的响应: 进展与问题. 地球科学进展, 2010,25(3):233-241.]
[8]	Sumer B M . Mathematical modeling of scour: A review. Journal of Hydraulic Research, 2007,45(6):723-735. doi: 10.1080/00221686.2007.9521811
[9]	Zheng Shuwei, Cheng Heqin, Shi Shengyu , et al. Impact of anthropogenic drivers on subaqueous topographical change in the Datong to Xuliujing reach of the Yangtze River. Science China Earth Sciences, 2018,48(5):628-638.
	[ 郑树伟, 程和琴, 石盛玉 , 等. 长江大通至徐六泾水下地形演变的人为驱动效应. 中国科学: 地球科学, 2018,48(5):628-638.]
[10]	Zhang Xiaohe, Li Jiufa, Zhu Wenwu , et al. Study on recent bed changes of erosion and siltation in Yangtze River Estuary. Acta Oceanologica Sinica, 2015,37(3):134-143.
	[ 张晓鹤, 李九发, 朱文武 , 等. 近期长江河口冲淤演变过程研究. 海洋学报, 2015,37(3):134-143.]
[11]	Jiang C, Li J, Swart H E D . Effects of navigational works on morphological changes in the bar area of the Yangtze Estuary. Geomorphology, 2012,139/140(2):205-219. doi: 10.1016/j.geomorph.2011.10.020
[12]	Ji Lan, Gong Hongfeng, Lou Fei . Preliminary study on navigation function orientation of Hengsha Passage at Yangtze Estuary. Port and Waterway Engineering, 2010(12):104-108.
	[ 季岚, 龚鸿锋, 楼飞 . 长江口横沙通道通航功能定位的初步研究. 水运工程, 2010(12):104-108.]
[13]	Guo Xingjie, Cheng Heqin, Ji Na , et al. Study on the influences of fluvial processes of Hengsha watercourse to deep water channel. Journal of Sediment Research, 2015(3):21-26.
	[ 郭兴杰, 程和琴, 计娜 , 等. 长江口横沙通道演变对北槽深水航道上段回淤的影响. 泥沙研究, 2015(3):21-26.]
[14]	Chen Wei, Gu Jie, Qin Xin , et al. Numerical analysis of the sediment deposition in the upper reach of the deepwater navigation channel in the Changjiang River Estuary. Chinese Journal of Hydrodynamics, 2012,27(2):199-207.
	[ 陈维, 顾杰, 秦欣 , 等. 数值分析长江口深水航道上段淤积的原因. 水动力学研究与进展, 2012,27(2):199-207.]
[15]	Wu Shuaihu, Cheng Heqin, Xu Yijun , et al. Observation and analysis of bedform morphology of the Yangtze River estuary. The Ocean Engineering, 2016,34(6):65-73.
	[ 吴帅虎, 程和琴, 胥毅军 , 等. 长江河口主槽地貌形态观测与分析. 海洋工程, 2016,34(6):65-73.]
[16]	Liu Gaowei . The variations in hydrodynamic, depositional and geomorphology in the Yangtze Estuary for the recent years[D]. Shanghai: East China Normal University, 2015.
	[ 刘高伟 . 近期长江河口典型河槽动力沉积地貌过程[D]. 上海: 华东师范大学, 2015.]
[17]	Zheng Shuwei, Cheng Heqin, Wu Shuaihu , et al. Discovery and implications of the catenary-bead subaqueous dunes. Science China Earth Sciences, 2016,46(1):18-26.
	[ 郑树伟, 程和琴, 吴帅虎 , 等. 链珠状沙波的发现及意义. 中国科学: 地球科学, 2016,46(1):18-26.]
[18]	Cheng Heqin, Li Maotian, Zhou Tianyu , et al. High-resolution micro-topography movement in the Changjiang Estuary. The Ocean Engineering, 2002,20(2):91-95.
	[ 程和琴, 李茂田, 周天瑜 , 等. 长江口水下高分辨率微地貌及运动特征. 海洋工程, 2002,20(2):91-95.]
[19]	Mao Zhichang, Wu Xiaoyong, Zhao Changqing , et al. Evolution of the upper reach of mouth bars in the North Channel of the Changjiang Estuary. Journal of Sediment Research, 2008(2):41-46.
	[ 茅志昌, 武小勇, 赵常青 , 等. 长江口北港拦门沙河段上段演变分析. 泥沙研究, 2008(2):41-46.]
[20]	Zhu Jianrong, Bao Daoyang . The effects of river regime changes in the Changjiang Estuary on hydrodynamics and salinity intrusion in the past 60 years: Ⅰ. River regime changes. Acta Oceanologica Sinica, 2016,38(12):11-22.
	[ 朱建荣, 鲍道阳 . 近60年来长江河口河势变化及其对水动力和盐水入侵的影响: Ⅰ. 河势变化. 海洋学报, 2016,38(12):11-22.]
[21]	Zhang Ruijing, Xie Jianheng, Chen Wenbiao . River Dynamics. Wuhan: Wuhan University Press, 2007: 163-164.
	[ 张瑞瑾, 谢鉴衡, 陈文彪 . 河流动力学. 武汉: 武汉大学出版社, 2007: 163-164.]
[22]	Xie Huijiao, Shen Wei . Analysis of reclamation of Changxing island in Hengsha passageway//Anthology of the Twelfth National Conference on Hydrodynamics, 2013: 1013-1018.
	[ 谢慧姣, 沈薇 . 长江口长兴岛东岸圈围对横沙通道影响分析//全国水动力学学术会议, 2013: 1013-1018.]
[23]	Cheng Haifeng, Liu Jie, Zhao Dezhao . Analysis of river bed evolution and prediction of its trend for Hengsha Passage. Journal of Waterway and Harbor, 2010,31(5):365-369.
	[ 程海峰, 刘杰, 赵德招 . 横沙通道近期河床演变及趋势分析. 水道港口, 2010,31(5):365-369.]

年份	2001年	2005年	2009年	2011年	2014年	2017年
体积(万m³)	164.6	237.6	336.1	390.5	437.4	537.7
面积(万m²)	7.9	11.4	14.6	15.8	16.5	19.4
平均深度(m)	20.83	20.84	23.02	24.72	26.51	27.72

	1984年	1992年	2001年	2005年	2009年	2017年
河槽体积(万m³)	3078.12	3438.10	5132.86	5851.68	5602.12	6530.30
河槽平均深度(m)	5.99	6.65	8.73	9.98	9.45	10.67

Formation mechanism of near-shore erosional topography in the Hengsha passage of the Yangtze Estuary

RichHTML

PDF (PC)

Like

Knowledge

Abstract

Cite this article

share this article

Figures/Tables 10

References 23

Related Articles 15

Metrics

Comments

[1]	DONG Guanghui, QIU Menghan, LI Ruo, CHEN Fahu. Using the Fulcrum Cognitive Model to explore the mechanismof past human-land co-evolution [J]. Acta Geographica Sinica, 2021, 76(1): 15-29.
[2]	XU Jun, XU Yang, HU Lei, WANG Zhenbo. Discovering spatio-temporal patterns of human activity on the Qinghai-Tibet Plateau based on crowdsourcing positioning data [J]. Acta Geographica Sinica, 2020, 75(7): 1406-1417.
[3]	YI Jiawei, WANG Nan, QIAN Jiale, MA Ting, DU Yunyan, PEI Tao, ZHOU Chenghu, TU Wenna, LIU Zhang, WANG Huimeng. Spatio-temporal responses of urban road traffic and human activities in an extreme rainfall event using big data [J]. Acta Geographica Sinica, 2020, 75(3): 497-508.
[4]	Guangliang HOU, Guangchao CAO, Chongyi E, Xiaoyan REN, B Wuennemann, Fan LI. New evidence of human activities at an altitude of 4000 meters area of Qinghai-Tibet Plateau [J]. Acta Geographica Sinica, 2016, 71(7): 1231-1240.
[5]	Yong XU, Xiaoyi SUN, Qing TANG. Human activity intensity of land surface: Concept, method and application in China [J]. Acta Geographica Sinica, 2015, 70(7): 1068-1079.
[6]	Baohua ZHOU, Jian YIN, Baoshi JIN, Lei ZHU. Degradation of Wuchang Lake wetland and its causes during 1980-2010 [J]. Acta Geographica Sinica, 2014, 69(11): 1697-1706.
[7]	HOU Guangliang, WEI Haicheng, E Chongyi, SUN Yongjuan. Human activities and environmental change in Holocene in the northeastern margin of Qinghai-Tibet Plateau: A case study of JXG2 relic site in Qinghai Lake [J]. Acta Geographica Sinica, 2013, 68(3): 380-388.
[8]	HE Yufang, CHENG Heqin, CHEN Jiyu. Morphological Evolution of Mouth Bars of the Yangtze Estuarine Waterways in the Last 100 Years [J]. Acta Geographica Sinica, 2011, 66(3): 305-312.
[9]	PANG Ruiming, XU Qinghai, DING Wei, ZHANG Shengrui. Pollen Assemblage of Farmlands in Central and Southern Hebei Province [J]. Acta Geographica Sinica, 2010, 65(11): 1345-1354.
[10]	XU Jiongxin. A Study of Sediment Sink between Longmen and Sanmenxia on the Yellow River [J]. Acta Geographica Sinica, 2009, 64(5): 515-530.
[11]	OU Dongni, LIU Min, XU Shiyuan, CHENG Shubo, HOU Lijun, WANG Lili. Polycyclic Aromatic Hydrocarbons Sources Identification Based on Multiple Indices from the Yangtze Estuarine and Nearby Coastal Areas [J]. Acta Geographica Sinica, 2008, 63(5): 535-543.
[12]	DAI Shibao, YANG Shilun, CAI Aimin. Variation of Sediment Discharge of the Pear l River Basin from 1955 to 2005 [J]. Acta Geographica Sinica, 2007, 62(5): 545-554.
[13]	LIU Min, HOU Lijun, XU Shiyuan, OU Dongni, JIANG Haiyan, YU Jie, GARDNER Wayne S. Carbon and Nitrogen Stable Isotopes as Tracers to Source Organic Matter in the Yangtze Estuary [J]. Acta Geographica Sinica, 2004, 59(6): 918-926.
[14]	ZHANG Lei, LIU Yi. An Analysis on Man-Land Relationship of Eastern China [J]. Acta Geographica Sinica, 2004, 59(2): 311-319.
[15]	LI Yuzhong, CHEN Shenliang. Similarities between Yangshan Harbor Sea Area and the Yangtze Estuary [J]. Acta Geographica Sinica, 2002, 57(6): 662-670.